Problem dated back to 2008,,, ya well it goes back further then that! I bought my RV-4 in 2005, the Champion Fine Wire plugs where installed in 1989 and had 900 hours on them when the engine began having troubles running properly at all times, the plugs ranged from 21m ohms to open, most being between 21m and 35m ohms, m as in million

I'm surprised it even ran at all.
In 2005 I installed Tempest Fine Wire (maybe they where before Tempest, maybe Autolite) and now have 1500 hours on them, there all reading below 1700 ohms.